The present invention relates generally to electronic connector systems and, more specifically, to low-profile connector systems for user-removable electronic modules, such as transceiver modules that interface with an electronic device, such as a computer, switch, subsystem, peripheral device, disk drive, tape drive and other input/output devices.
Electrical connectors are used to interconnect circuit cards and other electronic modules or assemblies in computers and other electronic devices. Various international and industry standards define the type of connectors used to interface computers or other devices to external communication devices such as modems, network interfaces, and other transceivers. A well-known type of transceiver developed by an industry consortium and known as a gigabit interface converter (GBIC) or serial optical converter (SOC) provides an interface between a computer or other electronic device and an Ethernet, Fibre Channel or other data communication environment. In co-pending U.S. patent application Ser. No. 09/216,104, a connector system is described that includes an optoelectronic transceiver module of this type that conforms to the Small Form Factor (SFF) standard. The SFF standard specifies a module enclosure 9.8 mm in height by 13.5 mm in width and allowing a minimum of 24 transceivers across a standard rack opening. The connector system includes a connector that is mountable on a circuit card of a computer or other electronic device and with which the transceiver module can be removably joined for electrical connection. The connector has a guide rail and cam system that facilitates mechanical mating with the transceiver module. The connector can be mounted on a circuit card behind a bezel of the enclosure of the computer or other electronic device, with the guide rail extending through an opening in the bezel. The connector further has a connector block with an array of electrical contacts that facilitate electrical connection with complementary contacts of the transceiver module. A user electrically connects the transceiver module with the connector by sliding the module over the end of the guide rail that protrudes through the bezel, and sliding it along the guide rail until the cam fully engages the transceiver module and fill mechanical and electrical contact is established. At approximately the point at which the transceiver module becomes fully engaged with the connector, a latch member at the distal end of the guide rail engages a complementary latch member on the module.
Because the guide rail of the above-described connector system protrudes through the opening in the bezel, the latch member at its distal end is subject to being inadvertently bumped or jarred especially when the communication port is left open, i.e., no transceiver module is installed in the opening in the bezel. If the force of such an impact is severe enough, it could damage the latch or guide rail or damage the integrity of the soldered electrical connections between the guide rail and the circuit board upon which it is mounted.
In co-pending U.S. patent application Ser. No. 09/410,786, a connector system is described that includes a guide rail with a removable latch member at its distal end that snaps off if it experiences a jarring force to prevent damage. A snap engagement portion on the removable latch member mates with a mating snap engagement portion on the distal end of the guide rail. If the removable latch member snaps off, one can reattach it by snapping it back onto the guide rail. The removable latch member does not, however, address other problems that occur when the communication port is left open. One problem that is not addressed by the removable latch member is the escape of electromagnetic emissions from the computer or other electronic device through the open port. The escape of electromagnetic emissions may cause electromagnetic interference (EMI). Another problem not addressed by the removable latch member is the entry of dust into the computer or other electronic device through the open port.
It is known that an inwardly opening, metal door pivotally mounted within the computer or other electronic device may be used to reduce electromagnetic emissions and dust entry when no transceiver module is installed in the opening in the bezel. U.S. Pat. No. 5,767,999, issued Jun. 16, 1998 to Andrew H. Kayner and U.S. Pat. No. 5,879,173, issued Mar. 9, 1999 to Daniel S. Poplawski et al., for example, each disclose a door within the computer or other electronic device that is spring biased toward a closed position against the bezel. The door opens inwardly toward the inside of the computer or other electronic device as the removable transceiver module is inserted in the opening in the bezel. The bezel is made of metal and grounded by connection to the chassis of the computer or other electronic device. Because the door is made of metal and spring biased against the bezel when no transceiver module is installed in the opening in the bezel, the door serves to reduce electromagnetic emissions. The spring, however, does not always completely close the door when the removable transceiver module is absent. Sources of incomplete door closure include component failure, frictional variations, and spring force variations and deterioration. Incomplete door closure may result in the entry of dust into the computer or other electronic device and the escape of electromagnetic emission, especially at high frequencies. As electronic devices move to higher and higher frequencies of operation, incomplete door closure becomes more problematic. In addition, because the door is mounted within the computer or electronic device, it is difficult to replace or repair components thereof without opening the enclosure of the computer or electronic device. This likely necessitates turning off the computer or electronic device, thereby reducing its availability.
It would be desirable to minimize the likelihood of the above-described damage occurring to the latch member and effectively minimize the likelihood of the above-described escape of electromagnetic emission and entry of dust.